Flawed science has significantly contributed to wrongful convictions. Courts struggle with how to address such convictions when the mistaken science (such as bogus expert claims about the differences between accidental fires and intentionally set ones) significantly affected the guilty verdict but there is no DNA evidence to directly exonerate the accused. This article explores why prosecutors often defend bad science. Mistakes in science tend to serve the prosecution, but there are other more subtle factors that explain prosecutors’ reluctance to address flawed forensic testimony. Such reluctance may arise from fondness for the status quo and a resistance to subverting the authority of experts or questioning long-accepted courtroom traditions. Thus, many judges and prosecutors cling to established legal precedent even when the underlying science has been discredited.

This reflects, at least in part, larger intellectual and scientific debates; those who refuse to question previous orthodoxies may be expressing resistance to the whole scientific enterprise, which constantly calls for challenging and revising hypotheses, unsettling prior beliefs. Judges and prosecutors resisting challenges to questionable science seem to resent the challenge to established expert authority and reject the horrifying notion that convictions could have been wrongful. In the cases of bite mark and microscopic hair analysis (two discredited types of forensic expertise), some prosecutors display almost a religious fervor, insisting that each human being is identifiably and unmistakably unique, wrongly insisting that scientist can accurately differentiate among the bite marks and hairs of different people. After analyzing the culture of prosecutors’ offices and discussing how prosecutorial resistance to abandoning bad science reflects prosecutors’ self-image as justice seekers, the article suggest strategies and mechanisms for encouraging prosecutors to abandon bad science.